Preparation of detergent mixtures



United States PREPARATION OF DETERGENT MlXTURES Richard D. Stayner, Berkeley, Calif., assignor to California Research Corporation, 52:: Francisco, Calif., a corporation of Delaware No Drawing. Application June 29, 1954 Serial No. 440,238

Claims. (Cl. 252-152) of vegetable and animal origin, for instance, coconut oil,

palmnut oil, hydrogenated tallow, hydrogenated cottonseed oil, hydrogenated soybean oil, hydrogenated whale oil, and the like materials. These sulfated alkylolamides are prepared by reacting the corresponding fatty acids with primary or secondary C -C alkylolamines, and preferably C -C alkylolamines, sulfating the resulting alkylolamides and neutralizing the acid sulfates with a suitable base.

The term monoalkyl benzene sulfonates, as employed hereinafter, shall refer to water-soluble salts of C9-C1a monoalkyl benzene sulfonic acids such as are produced by sulfonating various alkyl benzene stocks, e. g., polypropylene benzenes, described in U. S. Patent No. 2,477,- 382, to A. H. Lewis; keryl benzenes, described at page 122, of the book Surface-Active Agents, by Schwartz and Perry (1949); C -C alkyl benzenes in which the alkyl chain is derived from the olefins obtained by the Fischer-Tropsch synthesis; and other suitable alkyl benzene hydrocarbons.

A large number of detergent formulations containing mixtures of different anionic detergent compounds have been proposed in the art. Generally, in these mixtures, one of the detergent components imparts some particular beneficial property, or properties, to the finished detergent formulation, for instance, an easier solubility or of the detergent components of such a mixture is consid- L erably less expensive than the other detergent component, although the detergency of the mixture is equivalent, or almost equivalent, to the detergency of the second component when employed as the only detergent ingredient in the amount equal in weight to the weight of the mixture.

Sulfated alkylolamides of higher C -C saturated fatty acids are considered by the art to be efficient detergents and lime-soap dispersants. Although these characteristics render sulfated alkylolamides of higher fatty acids attractive to the user, their foams do not possess sufficient persistence. This constitutes somewhat of a drawback, owing to the preference of a large number of small scale users of synthetic anionic detergents for products capable of creating a substantial volume of dense foam similar in consistency to that of soapsuds. In fact, the formation of a copious foam is often accepted by the 2,822,335 Patented Feb. 4, 1958 user as a criterion of the proper quantity of detergent to be used in preparing a washing solution; and persistence of the foam is thought to he an indication that the washing ability of the detergent is not spent. By the lack of sufficient foam persistence is meant inability of dilute aqueous solutions of the sulfated alkylolamides to form a foam that would endure under the conditions of agitation and in the presence of soiled clothes and fabrics in an agitator-type washing machine.

It has been proposed to remedy this inability to form persistent foam by preparing mixtures of detergent sulfated alkylolamides and detergent'monoalkyl benzene sulfonates. These mixtures were to contain a suflicient proportion of sulfated alkylolamides, preferably not less than 15% by weight, based on the entire content of surface-active organic materials in a particular detergent formulation, so as to impart to this formulation the desirable properties of sulfated alkylolamides. Furthermore, these mixtures were to contain detergent monoalkyl benzene sulfonates in an amount adding up to by weight with the content of sulfated alkylolamides, in order to facilitate formation of sufficient quantity (volume) of foam in the solution of a mixture of these two detergents. Although the foam of monoalkyl benzene sulfonates is lacy and of a rather weak texture incapable to withstand continued agitation, the presence of a large volume of this foam assists the foam of the sulfated alkylolamide component in enduring, despite the agitation in the presence of soil, throughout the complete washing cycle of 20 minutes or more in the tub of a washing machine, particularly in the presence of foamstabilizing additives, such as straight-chain C -C saturated aliphatic alcohols, straight-chain C C alkyl or acyl phenols and straight-chain C C saturated fatty acid amides, described in my patent applications: Serial No. 413,713, filed March 3, 1954; Serial No. 420,183, filed March 31, 1954; and Serial No. 422,240, filed April 9, 1954, respectively. This ability to produce persistent foam is an important property in a detergent formulation, because it is one of the main factors motivating the purchase by the consumer of a synthetic detergent formulation which resembles in its foam behavior that of the conventional, good-quality soap.

Compared with the straightforward and easily-controlled preparation of monoalkyl benzene sulfonate detergent materials suitable for use in the proposed mixtures of monoalkyl benzene sulfonates and sulfated alkylolamides, the preparation of sulfated alkylolamides of higher fatty acids is not as simple an operation, due to the chemical instability of both the alkylolamides of higher fatty acids and of their acid sulfates. First of all, in the conventional preparation of alkylolamides by reacting a primary and/ or a secondary alkylolamine with a higher saturated straight-chain fatty acid, small amounts of amino-esters are ordinarily formed. These esters cannot be sulfated to form sulfuric acid esters nor can they be readily separated from the alkylolamides. Consequently, upon sulfation of the alkylolamide material, they remain in the sulfated alkylolamide product and detract from its surface-active properties. Although formation of these amino-esters can be minimized by employing an excess of the corresponding alkylolamine for the reaction with fatty acids, sulfation of alkylolamides in accordance with the conventional procedures gives rise to additional difficulties. Both the alkylolamides and their acid sulfates tend to decompose and undergo rerrangement in contact with sulfuric acid or other strong sulfating agents, at a temperature of about 40 C. or higher. At lower temperatures the high melting alkylolamides do not sulfate very readily and, in contact with sulfuric acid employedin a stoichiometric excess to insure completeness of the-sulfation reaction, they slowly decompose, undergoing rearrangement to amino-esters and other undesirable by-products. The formation of these by-products is further aggravated by the lack of solubility in sulfuric :acid'of the allrylolamides of higher saturated fatty acids, particularly of those fatty acids derived from hydrogenated tallow or similar materials. In addition, the sulfated alkylolamides, likewise being insoluble in sulfuric'acid, decompose andrearrang'e after a relatively short period of contact with sulfuric acid, particularly at temperaturesabove 50 (3., theres'ult being a reduction of the yield and impairment of the surfaceactive properties of the ultimate sulfated alkylolamide product.

The k-nown techniques, employed in the art to palliate the violence of the sulfation reaction at high tempera tures (-i. e., above'the 40 50 C. range) and to'reducc occurrence of side-reactions, are of no-avail in the sulfation of alkylolamides of higher saturated fatty acids. Application of conventional organic solvents or diluents, e.;g., chloroform, methylene chloride, carbon tetrachloride, etc., is of not much help either, since the alleyloh amides as wellas sulfuric acid are-not appreciably'soluble in such solvents. As mentioned 'hereinbefore, sulfation temperatures below the commonly employed temperature range of 40m 50 C. slow down the reaction and increase the production costs. On the other hand, sulfation temperatures above this range promote the occurrence of side-reactions, increase the amount of undesirable by-products, and markedly lower the yield and the quality of the final product. Lengthening or shortening of the time of reaction is likewise ineffective: If the contact between the alkylolamide and sulfuric acid is too short, the reaction of sulfation is not completed; if the contact time between the alkylolamide and the acid is too long, the amount of undesirable lay-products increases, while the quality and the yield of the alkylolamide sulfate product correspondingly suffer.

Satisfactory preparation of sulfated alkylolamides was reported to have been made possible by a very rigid control of the temperature. This method, however, required special refrigeration equipment and a thorough mixing of the reactants, all of which greatly increase the production costs. Even then, the foam performance of the resulting alkylolamide sulfate product in dilute aqueous wash solutions thereof was unsatisfactory, apparently still owing to the presence of aminoesters and/ or of other contaminating by-products.

it has been proposed to prepare, first, a sulfuric ester of alkylolamine and to react this ester with a fatty acid chloride, thereby by-passing the sulfation step attended n tioned difficulties observed in the preparation of sulfated alkylolamides of higher saturated fatty acids, mixtures of these detergent alkylolamide sulfates and monoalkyl benzene sulfonatcs suitable for the formulation of detergent compositions characterized by improved foam performance, i. e., better quality and persistence of foam under agitation, can be prepared in an efficient manner by first sulfonating an alkyl benzene material to provide a mix ture of monoalkyl benzene sulfonic acid and sulfuric acid, and subsequently sulfating an alkylolamide or alkylolamides of higher fatty acids in the sulfonation reaction product mixture. In this manner, formation of byproducts during the sulfation of the alkylolamides is substantiallyreduced, if not totally eliminated, enabling production of efiicient detergent mixtures of sulfated alkylolamides and alkyl benzene sulfonates, characterized, in

addition, by excellent foam performance in aqueous wash solutions under conditions of agitation and in the presence of soil.

I have found that sulfonated hydrocarbons, i. '-e., siilfo'nic acids of the general formula: -RSO H, wherein R may be any conveniently available hydrocarbon, when present in the reaction of sulfation of valleylolamide by sulfuric acid, solubilize the .alkylolamides of higher saturated fatty acids. This uriexpected property permits a rapid sulfation of alkylolamides with the minimum of decomposition and minimum production of undesirable non-detergent by-products.

The preferred embodiment of the preparationof mixtures of detergent alkylolarnide sulfates and detergent monalkyl benzene sulfonates inaccordancewithtmyiim vention involves sulfonationof suitable 'allayl benzene materials with an excess of sulfuric a'oid varying in strength from about 95% H up to 30% oleum, the mol ratio of the acid to the alkyl benzene "raii'g'ing from about 2.5 to about 5.5 mols, and preferably from about 3 to about 4.5 mols. This ratio refers "to mols of equivalent 100% H 80 per one mol of alkyl benzene, regardless of the strength of the acid actually employed. Details of such sulfonationcan be found at pages 4 to 10 of the bulletin published by Oronite Ghemicalfiompany of San Francisco, California, under the title -Alkane- Product and Processing Information. I

During the sulfonation, the'strength-of-thesulfuriq{acid is reduced, now ranging from 5% ole-um to as low 3.818Q'% H 30 depending upon the initial-ratio of the acid to'fhe alkyl benzene. Therefore, on completion of thesulfon'anon-treatment, it becomes necessary to adjust theetrength of the'acid to the desired value from about-% AIIQSO to about 2% oleum, and preferably from about to about H 80 by introducing additional acid or S0 or by diluting the sulfonation product --mixture with water. Theadjustment of the acid strength in thersul-fonation reaction product mixture is governed bv'the following considerations: (a) The amount of alkylolamide to be sulfated; (b) the desireof attaining the -maximurn of conversion, since the weaker the acid, *thelowerjthe-conversion; (c) the color of the sulfated alkylolamide prodnot, which is a function of the sulfation-temperature; should this temperature be too high, additionalcooling means are required to prevent degradation' of the color. On the other hand, should'this temperature be too l ow, the reaction mixture becomes too viscous, the-reaction itself is slowed down and conversioncorrespondingly'decreases. k

Having adjusted the acid strength in-the sul-fonatio n product mixture, the alkylolamide material can be-added thereto, andthe whole-"is then digested -.at*a temperature from about 30 to about 60 C., the temperature range from about 40 to about 50 C. beingpreferred, Ordinarily, whenever one mol of alkyl benzene is sulfonated at mol ratios of the acidto the allgyl benzene within the aforementioned range from about 2.5 to about T55, and preferably from about 3 to about 4.5, the amounts of't-he alkylolarnide which may be effectively sulfated, upon adjusting the acid strength of the sulfonation reaction'mixture to from about 90% H 80 to-about 2% oleumfwill be in the range from 0.25 to l molpereach inol of the initial alkyl benzene stock. Of course, the desired weight ratio of the alkylolamide sulfate to the alkylibenzene sulfonate in the ultimate mixed detergent product controls the choice of a proper quantity of thealkylolamideto be added to the sulfonation-product mixture, and thischoice is, furthermore, dependent on the choice of the right temperature in the aforementioned operating temperature,

The alkylola'mide material may be added 'ito -tlie tsul fonation reaction mixture in any suitable manner, for instance, by dissolving the amide in a solvent inert to sulfuric acid and sulfonic acid, by melting the amide and dispersing the melt in the sulfonation reaction mixture, or finally by reducing the alkylolamide material to a finely subdivided particle form, such as flakes or beads, and dispersing these particles in the liquid-phase sulfonation mixture.

In some cases it may be desired that the sulfonating agent (oleum or 95100% sulfuric acid) be employed in such amount as to leave insufficient sulfuric acid to sulfate all of the alkylolamide. If no adjustment of sulfuric acid is then made to provide for the presence of the necessary excess of sulfuric acid of the desired strength, a portion of the alkylolamide material will remain unsulfated in the mixture of acid sulfated alkylolamides and alkyl benzene sulfonic acid. The presence of such unreacted alkylolamide will tend to impart stability to the foam formed by aqueous Wash solutions of the final detergent formulation and will furthermore improve the soil tolerance of this foam.

Upon completion of the sulfation treatment, the mixture of acid alkylolamide sulfate and alkyl benzene sulfonic acid is neutralized with a base (e. g., sodium hydroxide or sodium carbonate) capable of forming an queous slurry or solution of a mixture of water-soluble detergent salts of sulfated alkylolamides and alkyl benzene sulfonic acids. Inorganic detergent builders and other conventional additives which may be required by the specification for a particular detergent formulation can be added at this point to the neutralized slurry, or solution, which is then converted to the desired solid-particle form by known drying techniques.

The inorganic builders which may be present in the detergent formulations containing mixtures of detergent sulfated alkylolamides and alkyl benzene sulfonates are inorganic salt detergent builders, by which term is meant neutral inorganic salts of strong inorganic acids and alkaline salts of weak inorganic acids, compatible with the organic detergent materials and tending to improve their surface-active properties.

As illustrations of these builders, the following may be named: alkali metal and ammonium sulfates, carbonates, silicates, borates, and various polyphosphates, sodium salts being preferably so employed. The other conventional additives, usually present in small amounts of less than 5% by weight of the total finished solid detergent formulation, include anti-caking agents, e. g., sodium benzene sulfonate or sodium toluene sulfonate, opticalbleaches, perfume, coloring agents, carboxymethyl cellulose and kindred detergent extenders, N-alkyl glycines and N-alkyl diglycines as skin emollients, and C -C alkylolamides of higher saturated C8C18 fatty acids, which contribute to enhance the soil tolerance of the foam, e. g., lauric isopropanolamide, lauric glycerolamide,

Example 1 To 1 mol (245 g.) of C -C polypropylene benzene, cooled to a temperature of 5 C., 3.9 mols (365 g.) of 22% oleum were gradually added with stirring over a period of about minutes. The reaction mixture was cooled by means of an ice-water bath, and, towards the end of the addition, the cooling was discontinued to allow the temperature to rise. The reaction mixture was digested for 1 hour at to C., whereupon 0.54 mol (173 g.) of stearic acid ethanolarnide (stearic acid having been derived from hydrogenated tallow) was added as a molten liquid. The addition took about minutes, the temperature being maintained at about 40 C. by means of occasional cooling. After the stearic ethanolarnide was added to the sulfonation product mixture, the resulting mixture was digested between 44-48 C. for

1 /2 to 2 hours and neutralized with the aid of a solution of NaOH. The slurry was then ready to receive theadtion of inorganic detergent builders and such other'additives as may have been required by a particular specification, prior to spray-drying it to the desired solid particle form.

Example 2 In another illustrative example of the practice of my invention, 0.6 mol (146 g.) of a C -C polypropylene benzene was placed into a 2-liter three-necked flask equipped with a stirrer, a thermometer and a dropping funnel. The contents of the flask were cooled to 5 C., and 3 mols (280 g.) of 20% oleum were added gradually over a 45 minute period from the dropping funnel, continuously cooling the flask to maintain the temperature at 10 When the addition was finished, the mixture was digested for 40 minutes at 30 to 35 C. and the contents were finally cooled at 25 C. Thereupon, ethanolamide of stearic acid obtained from hydrogenated tallow was added to the cooled mixture in an amount to 0.5 mol (157 g.) in the form of crushed flakes over a period of 20 minutes. When the addition was terminated, the resulting mixture was digested from /2 to 2 hours at 40 to 45 C., and finally was neutralized with caustic to give an aqueous slurry having a light yellow color. After adding the necessary organic builders and other specified additives and spray-drying, a white detergent powder was obtained which contained 20% by weight of an organic mixture of alkylolamide sulfate, alkylolamide and alkyl benzene sulfonates. The foam performance, i. e., the quality, stability and persistence of the foam of dilute aqueous solutions prepared with mixed detergent compositions containing sulfated alkylolamides of higher saturated fatty acids is highly satisfactory, as well as their detergency which favorably compares with the detergencies of a number of popular efficient detergents of the trade. The data on foam performance and detergency can be found in my copending application Serial No. 420,183, mentioned hereinbefore.

Although in the aforegiven description of the preparation of detergent mixtures of sulfated alkylolamides of higher saturated fatty acids and alkyl benzene sulfonates, sulfuric acid in excess and varying in strength from 30% oleum down to 95% sulfuric acid has been suggested as the sulfonating agent for the production of the sulfonated hydrocarbon (alkyl benzene sulfonic acid) which is to serve in the subsequent sulfation of the alkylolamide as a solubilizing medium for the alkylolamide material, other appropriate sulfonation techniques may be employed to produce the necessary sulfonated hydrocarbon solubilizer. For instance, the hydrocarbon, such as alkyl benzene, may be sulfonated in a known manner with sulfur trioxide or chlorosulfonic acid, care being taken not to use an excess of either of these powerful sulfonating agents and to separate any remaining reactive sulfur trioxide or sulfonyl chloride from the sulfonation product mixture. Thereafter, excess of sulfuric acid varying in strength from to 100%, and preferably from to strong, is admixed to the sulfonated hydrocarbon, such as alkyl benzene sulfuric acid, and the alkylolamide to be sulfated is added to the mixture of sulfuric and sulfonic acids, either as a melt or in a finely comminuted state (e. g., as flakes). The mixture is then digested at 30 to 60 C. to complete sulfation of the alkylolamide, and the sulfation product is neutralized, yielding a slurry of water-soluble alkylolamide sulfates and alkyl benzene sulfonates. Following the addition of detergent builders and such other additives as may be specified, the slurry is dried to the desired particle form and size. As indicated hereinbefore, the term sulfonated hydrocarbon refers to sulfonic acids, such as straightand branchedchain alkane sulfonic acids, cycloalkane sulfonic acids, alkylcycloalkane sulfonic acids, alkyl aryl sulfonic acids (including alkyl benzene and alkyl naphthalene sulfonic acids), sulfonic acids. of alkylated heterocyclic compounds and aralkyl aryl sulfonicacids (i. e., sulfonic acids in which the aromatic nuclei are linked through a methylene group). These sulfonic acids may be prepared be forehand and then employed as solvents or solubilizing OfrfllkYlOlfllIlidO sulfates with a variety of sulfonates,

endowed with varying degrees of surface-activity, possessmg. valuable characteristics, and suitable for a number of. specialized applications,

Example 3 In another illustrative example, a mixture of 2.0 mol-s (1.96 g.) of 100% H SO and,0.51 mol (156 g.) of nhexadecane sulfonic acid was heated to 40 C., whereupon 0.40 mol (127 g.) of stearic ethanolamide was added ascrushed flakes to the acid mixture. After completing. the addition of the alkylolamide in about minutes, the mixture wasdigested at. 43-47 C. for 2 hours and neutralized with a solution of caustic. Theneutralized sulfation product mixture or slurry contained sodium n-hexadecane sulfonate and sodium sulfate of the ethanolamideof stearic acid. It was then reduced to small solid particles by drying the neutralized slurry in a spray drier.

Whenever the. particular sulfonated hydrocarbon itself is a solid, a sufiicient amount thereof may be dissolved in an appropriate solvent inert to sulfuric acid under the conditions prevailing inthe sulfation of alkylolamidesby sulfuric acid, so as to enable the dissolved sulfonatedalkylolamides inthe course of their sulfation in the aforedescribed temperature range from about to about 60 C.', and preferably from about to about C., and employing an excess of sulfuric acid having-a. strength from 80 to 100%.,and preferably from 95 to 100%.

While certainpreferred embodiments of the invention and, specific examplesillustrating the same have been given hereinabove, it willbe understood that the invention in its broader aspects is not limited thereby and includes within its scope production of mixtures of sulfated allcylolamides of any saturated fatty acids, irrespective of. the number of carbon atoms in its acyl portion, Withany suitable sulfonatedhydrocarbon by reacting acorresponding alkylolamide with sulfuric acid in the presence of. such sulfonated hydrocarbon in liquid phase as a solubilizer or solvent for the alkylolamide. In addition, it will be understood that any modifications or variations of the aforedescribed process which do not depart from theispirit and scope of the invention are to be included Within the definitions of the following claims.

I claim:

1. A process for preparing mixtures of C C; monoalkyl benzene sulfonates and sulfated C -C alkylolamides of straight-chain C -C saturated fatty acids by sulfonating. a ,C -C monoalkyl benzene with an excess of sulfuric acid varying in strength from 95% H 50 to 30% oleum in a ratio. from about 2.5 to about 5.5 mols of 100% H 80 per one mol of said C9-C13 monoalkyl benzene to form a mixture of a C C monoalkyl benzene sulfonic acid and free sulfuric acid; adjusting the strength offree sulfuric acid in the. sulfonation reaction product mixtureto obtain an excess of sulfuric acid having an acid ,strengthfrom about,90% H to about 2% oleum; adding ,to ,the mixture ofsaid sulfonic and freesulfuric acidsfrom 0.25, to aboutl mol of a C -C alkylolamide of a. straight chain (387C133 saturatedfatty acid; digesting themixtureuofacidsand alkylolamide at about 30 to about 60 C. to sulfate the alkylolamide; neutralizing the sulfation reaction product mixture with a base to form a mixture of C &,C monoalkyl benzene sulfonates and sulfated C -C alkylolamides of straight-chain C C saturated. fatty acids; .aud drying this mixture to the solidparticle form.

2. A process for preparing mixtures of C C polypropylene benzene sulfonates and sulfated C -C alkylolamides of straight-chain C C saturated fatty acids by sulfonating a Gig-C15 polypropylene benzene with an excess of. sulfuricacid varying in strength from 95% H 50 to 30%. oleum-in a ratio from about 2.5 to 5.5 mols of 100% H S O per onemol of. said polypropylene benzene to form a mixture of C -C polypropylene benzene sulfonic acid and free sulfuric acid; adjusting the strength of free sulfuric acid inthe sulfonation reaction product mixture to obtain an excess of sulfuric acid having an acid strength from about H SO to about 2% oleum; adding to the mixture of said polypropylene benzene sulfonic acidand free sulfuric acidfrom 0.25 to about 1 mol of a C -C alkylolamide of a straight-chain C -C saturated fatty acid; digesting the mixture of acids and alkylolamide at about 30 toabout 60 C. to sulfate'the alkylolamide; neutralizing; the sulfation reaction product mixturewith a base. to form a mixture of C -C polypropylene benzene sulfonates and sulfated C -C alkylolamides of straighbchain C -C saturated fatty acids; and drying this mixture to the solid particle form.

3. A process as defined in claim 1, wherein the mixture ofmonoalkyl benzene sulfonic acid, freev sulfuric acid and C -C alkylolamide of straight-chain C C saturated fatty acid is digested at a temperature from about 40 to about 50 C. to sulfate the alkylo'lamide.

4. A process as defined in claim 1, wherein themonoalkyl benzene is sulfonated with an excess of sulfuric acid varying in strength, from H 80 to 30% oleum in aratio from about.3.0 to about 4.5 mols of H 80 per one molof said monoalkyl benzene, and Wherein the strength of free sulfuric acid in the resulting sul fonationjreaction product mixtureis adjusted to provide an excess of sulfuric acid having an acid strength from about 95 to about,,l00,%, H 50 5. A: processes; defined in claim 1, wherein the alkylolamideg-of, straight chain,saturated fatty acid is a C 43 alkylolamide. of a-straightechain saturated hydrogenated tallowfatty: .acidand-said monoalkyl benzene is a C C polypropylene benzene.

References Cited in the file of this patent UNLTED STATES PATENTS 2,424,951 G lobus July 29, 1947 2,477,383 Lewis July 26, 1949 2,529,538 Henry Nov. 14, 1950 2,529,539 Brod Nov. 14, 1950 FOREIGN PATENTS 529,040 Great Britain Nov. 13, 1940 OTHER REFERENCES Surface Active Agents, Schwartz & Perry, Interscience Publishers Inc., New York, page 124 (1949). 

1. A PROCESS FOR PREPARING MIXTURES OF C9-C18 MONOALKYL BENZENE SULFONATES AND SULFATED C2-C7 ALKYLOLAMIDES OF STAIGHT-CHAIN C8-C18 SATURATED FATTY ACIDS BY SULFONATING A C9-C18 MONOALKYL BENZENE WITH AN EXCESS OF SULFURIC ACID VARYING IN STRENGTH FROM 95% H2SO4 TO 30% OLEUM IN A RATIO FROM ABOUT 2.5 TO ABOUT 5.5 MOLS OF 100% H2SO4 PER ONE MOL OF SAID C9-C18 MONOALKYL BENZENE TO FORM A MIXTURE OF A C9-C18 MONOALKYL BENZENE SULFONIC ACID AND FREE SULFURIC ACID; ADJUSTING THE STRENGTH OF FREE SULFURIC ACID IN THE SULFONATION REACTION PRODUCT MIXTURE TO OBTAIN AN EXCESS OF SULFURIC ACID HAVING AN ACID STRENGTH FROM ABOUT 90% H2SO4 TO ABOUT 2% OLEUM; ADDING TO THE MIXTURE OF SAID SULFONIC AND FREE SULFURIC ACIDS FROM 0.25 TO ABOUT 1 MOL OF A C2-C7 ALKYLOLAMIDE OF A STRAIGHT-CHAIN C8-C18 SATURATED FATTY ACID; DIGESTING THE MIXTURE OF ACIDS AND ALKYLOLAMIDE AT ABOUT 30 TO ABOUT 60*C. TO SULFATE THE ALKYLOLAMIDE; NEUTRALIZING THE SULFATION REACTION PRODUCT MIXTURE WITH A BASE TO FORM A MIXTURE OF C9-C18 MONOALKYL BENZENE SULFONATES AND SULFATED C2-C7 ALKYLOLAMIDES OF STRAIGHT-CHAIN C8-C18 SATURATED FATTY ACIDS; AND DRYING THIS MIXTURE TO THE SOLIDPARTICLE FORM. 